3.16.83-rc1 review patch. If anyone has any objections, please let me know.
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From: Johan Hovold johan@kernel.org
commit 3e4f8e21c4f27bcf30a48486b9dcc269512b79ff upstream.
Amend the endpoint-descriptor sanity checks to detect all duplicate endpoint addresses in a configuration.
Commit 0a8fd1346254 ("USB: fix problems with duplicate endpoint addresses") added a check for duplicate endpoint addresses within a single alternate setting, but did not look for duplicate addresses in other interfaces.
The current check would also not detect all duplicate addresses when one endpoint is as a (bi-directional) control endpoint.
This specifically avoids overwriting the endpoint entries in struct usb_device when enabling a duplicate endpoint, something which could potentially lead to crashes or leaks, for example, when endpoints are later disabled.
Signed-off-by: Johan Hovold johan@kernel.org Acked-by: Alan Stern stern@rowland.harvard.edu Link: https://lore.kernel.org/r/20191219161016.6695-1-johan@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/usb/core/config.c | 70 ++++++++++++++++++++++++++++++++------- 1 file changed, 58 insertions(+), 12 deletions(-)
--- a/drivers/usb/core/config.c +++ b/drivers/usb/core/config.c @@ -169,9 +169,58 @@ static const unsigned short super_speed_ [USB_ENDPOINT_XFER_INT] = 1024, };
-static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum, - int asnum, struct usb_host_interface *ifp, int num_ep, - unsigned char *buffer, int size) +static bool endpoint_is_duplicate(struct usb_endpoint_descriptor *e1, + struct usb_endpoint_descriptor *e2) +{ + if (e1->bEndpointAddress == e2->bEndpointAddress) + return true; + + if (usb_endpoint_xfer_control(e1) || usb_endpoint_xfer_control(e2)) { + if (usb_endpoint_num(e1) == usb_endpoint_num(e2)) + return true; + } + + return false; +} + +/* + * Check for duplicate endpoint addresses in other interfaces and in the + * altsetting currently being parsed. + */ +static bool config_endpoint_is_duplicate(struct usb_host_config *config, + int inum, int asnum, struct usb_endpoint_descriptor *d) +{ + struct usb_endpoint_descriptor *epd; + struct usb_interface_cache *intfc; + struct usb_host_interface *alt; + int i, j, k; + + for (i = 0; i < config->desc.bNumInterfaces; ++i) { + intfc = config->intf_cache[i]; + + for (j = 0; j < intfc->num_altsetting; ++j) { + alt = &intfc->altsetting[j]; + + if (alt->desc.bInterfaceNumber == inum && + alt->desc.bAlternateSetting != asnum) + continue; + + for (k = 0; k < alt->desc.bNumEndpoints; ++k) { + epd = &alt->endpoint[k].desc; + + if (endpoint_is_duplicate(epd, d)) + return true; + } + } + } + + return false; +} + +static int usb_parse_endpoint(struct device *ddev, int cfgno, + struct usb_host_config *config, int inum, int asnum, + struct usb_host_interface *ifp, int num_ep, + unsigned char *buffer, int size) { unsigned char *buffer0 = buffer; struct usb_endpoint_descriptor *d; @@ -208,13 +257,10 @@ static int usb_parse_endpoint(struct dev goto skip_to_next_endpoint_or_interface_descriptor;
/* Check for duplicate endpoint addresses */ - for (i = 0; i < ifp->desc.bNumEndpoints; ++i) { - if (ifp->endpoint[i].desc.bEndpointAddress == - d->bEndpointAddress) { - dev_warn(ddev, "config %d interface %d altsetting %d has a duplicate endpoint with address 0x%X, skipping\n", - cfgno, inum, asnum, d->bEndpointAddress); - goto skip_to_next_endpoint_or_interface_descriptor; - } + if (config_endpoint_is_duplicate(config, inum, asnum, d)) { + dev_warn(ddev, "config %d interface %d altsetting %d has a duplicate endpoint with address 0x%X, skipping\n", + cfgno, inum, asnum, d->bEndpointAddress); + goto skip_to_next_endpoint_or_interface_descriptor; }
endpoint = &ifp->endpoint[ifp->desc.bNumEndpoints]; @@ -481,8 +527,8 @@ static int usb_parse_interface(struct de if (((struct usb_descriptor_header *) buffer)->bDescriptorType == USB_DT_INTERFACE) break; - retval = usb_parse_endpoint(ddev, cfgno, inum, asnum, alt, - num_ep, buffer, size); + retval = usb_parse_endpoint(ddev, cfgno, config, inum, asnum, + alt, num_ep, buffer, size); if (retval < 0) return retval; ++n;